Precision coupling



oct.l 21, 1947. F, A, MILLE PRECISION coUPLING Filed Nov. 19, 1943Patented Oct. 214,

Buffalo Machinery oompanyp Inc.;

Buffalo',

N Y.; va corporation of N 'w York Application Novemberl 19, 1,943,--se'rii N6. 510,973 7 claims; (o1. 'e4-:30)

` The present invention relates vto the art of overload releasingcouplings and has for a primary obi-ect the provisionmoi such a couplingwhich functions with improved `preci sion. Another object of theinvention is to providea precision coupling constructed so that wear isreduced to a minimum.

A further o bject of the invention is the provi-Av sion of Aa couplingofthe aforesaid character which embodies improved lubricationcharacter-V 1s 1cs.

Still another object of theinvention is vto provide a vcoupling oitheabove. characterwhich is highly reliable foruautomatic operationWithin exceptionally close limits.

A still fur-ther object oi the invention istheY provision of acouplingdevice of the aforesaid nature which is relatively simple andcompact in construction and whichis applicable to various forms ofmechanism in which release oi overv loads or excessive torsional strainon machine parts is desired.

Figure 1 is a longitudinal sectional view throughV the assembledcoupling.

Figure 2 is a transverse section taken on lin-e 2-2 of Figure 1,

Figure 3 is a transverse section taken on line 3 3 of Figure 1, and

Figure 4 Ais ,a transverse sectional view taken on line 4 -4 of Figure1.

Referring to the drawingwhich illustrates a` preferred example or theinvention and wherein like reference characters denote correspondingparts throughout, I0 generally designates the female section of thecoupling embodyingV a cylindrical body II open at one end and vformedwith a diametrically reduced shoulder portion I2 exteriorly ofthe closedend. Prcjectingaxially outward of the shoulderlZ for connection with arotary mechanism is a tapered shank I3 integral with the shoulder. Atits inner side the shoulder l2 is formed with a socketl I 4 openingimward of the body and disposed centrally thereof,

At diametrically opposed sides the shoulder I2 is also formed withaxially extending through bores I5 interiorly threaded from their outerends to a point short ofthe inner end. E ach of thesefbores normallycarries a screw element I5 threaded into its outer` portion. Interiorlyof the circumfer-` ential wall of the body II are formed Yaplair ofellelly extending' .diemet'reeflly' Qppesedribs lef rectangular crosssection advantageously elongated circumferentially of the wall withtheir inner UQlCaYe edgfS. Qoncenllfc. With bod-Y 9fXS- These ribsextend from the end closing wall of the body lil teepointehert. of. theopposite open. end for apurposewhieh will be.hereinafterdescribed. Thebody-i interiorly screw threaded at its open end as -ineleeted @U18- lA- rneleseetien generally denoted at ile is designedgfor complementaryassembly with the vfea male sect-ion Ill` and constitutes a shaped headZtl cfa size suitable forslidable fitting with-A in the enen elf-1dY ofthe Section l0.. This head is alsoy provided with angannularrabbetedgroove 2-I in its .Outer peripheral. portion.. Extending axiallyoutward of the headZ and formed integral therewithis a .hel'lewQonnecting, shank 22 pro. vided with atapered axial bore 2 3 land atrans. versebore lintersecting theaxial bore at its inner end..Proieetinfe axially 4inward of the hea-d Zise; stud 2;5 -l1avin'g themellor lengthv from the head to apoint 4'slaortof its outer end ofnon-cire. cular advantageously square., cross section and havluga roundend extension -26 Within the cylindrical bodyvlgl is removalyflttedaset'of', inthe present. instance four,l frictionfmembers f 2' l inv the,present example vin the form 'of Aflat 'circular plates or disksprovided, at d-iametricallvopposed points", with indentations ornotches:28 opening atthe. periphery and de-A signed to slidablyengage theribsIl. VAs shown toi advantage'at Figures f1; and 4, the .friction disk-slhave-an exterior diameteraiording a sliding t wit-hin the socketll andare provided wi't'liv circular center openings 29 having a diameter`greater than the largesttransverse dimension of the stud 25.. Gn thestudV 25 are tted a set of. cofacting frio'- tion m'embersor disks 30,in the, present example' three, each of which has.' an Vexternaldiameter slightly less than the vdiametrical. dimension bee.

tween the inn-er edges n'o'f the ribs Il, and a central squareopenin'gI3| -of a 'site affording aslidin'g-t over the stud.

The coupling partsiare assembled by disposing the disks 2'! and 30 inalternate arr'.angementv Within the. rvSocket bb'dy With the 'studAXtened therethrough and having its end extension 26 rotatably tted intheV 'socket'. I4. .Such assembly brings the out-er face ofthe head 2U'alzproximate-A ly ush With thejopen'e'dge 'o'f the body IIY and theinner face of. t'ie'headinV abutment With or in. close proximity t'o.theouter ends of the ,ribs

ably tted Within. therebbetedsroove2l of the.

- heed. to removably .held the Sections .Operative assembly. A coiledcompression spring 33 is t- An exteriorly threaded. locking ring 32 is'.

ted within each of the bores I5 and compressed between the screw I6therein and the innermost friction disk 2l.

During operation, one of the co-axial shanks is connected with a drivingmember and the other connects with a driven member while the springs 33exert predetermined pressure against the friction members to cause thecoupling sections to rotate in unison under predetermined operatingconditions. Should the driven member be subjected to torsional strainexceeding a selected limit slippage between the sets of disks havingnonrotary connection with the respective coupling sections will resultso that the driving section will overrun the driven section to effectrelease 4 with the other set of disks on the other of the said membersbeing formed of non-ferrous metal having graphite mixed therewith saidcompression springs adapted to exert a predetermined amount of pressureon said friction elements.

2. Iri mechanism of the character described, a driving member saidmember having a cylindrical body, a shoulder portion on said body,vertical threaded bores in said shoulder portion, a driven member havinga disk shaped head co-axially related with the driving member,frictionally engageable means carried by the respective memof thelatter. The thrust or continual axial preslation could be made byadjustment of the screws ,K

IS and further varied by the use of springs of varying compression.

As can be observed from Figure 1, the friction disks connected forrotation with the respective male and female sections of the couplingare disposed to aiord a substantial overlapping relation to presentfrictional contacting surfaces of relatively large area. While the disksof one set, as for example the disks 39, may be constructed of ferrousmaterial such as cold rolled steel, those of the complementary set 2lare constructed to provide highly efficient lubrication at thecontacting surfaces coupled with suitably effective frictioncharacteristics. This is accomplished by forming one setv of the disksof a composition including bronze admixed with graphite. Such diskconstruction provides desirable qualities of lubrication while affordingsuicient friction between the contiguous faces to enable release withinone half to one per cent of torque increase on the driven section. Thus,conditions interfering with bers, said frictionally engageable meanscomprising a set of disks mounted on each of the said members forrotation therewith, the said sets of disks being disposed alternately inoverlapping arrangement, one of the said sets of disks being formed offerrous material and the other set being formed of non-ferrous metalhaving graphite mixed therewith and means mounted in the bores in saidshoulder portion for resiliently thrusting the said friction means intofrictional engagement.

3. In mechanism of the character described, a driving member said memberhaving a cylindrical body, a shoulder portion on said body, verticalthreaded bores in said shoulder portion, a driven member having a discshaped head co-axially related with the driving member, frictionallyengageable means carried by the respective members, said frictionallyengageable means comprising a set 0f disks mounted on each of the saidmembers for rotation therewith, the said sets of disks being disposedalternately in overlapping arrangement, one of the said sets of disksbeing formed of ferrous material and the other set berelease, such aslubricant adhesion, are completely eliminated and reliable overloadrelease is effected under all conditions including a wide range oftemperature variation and long periods of nonuse and Withinexceptionally close limits of torsional variance. The coupling has beenfound highly eicient for the application of a nosepiece to a shell,where great accuracy is essential and is advantageously useful forvarious other applications such as drill-press lathe and tapping machinework where prevention of tool breakage is highly desirable.

It is to be understood that the form of my invention herewith shown anddescribed is to be taken as a preferred example of the same and thatvarious changes relative to the material, size, shape and arrangement ofparts may be resorted to without departing from the spirit of theinvention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. In a coupling device having a drive member and a driven member acylindrical body on said drive member a shoulder portion on said body,vertical threaded bores in said shoulder portion, compression springs insaid bores, means for compressing said springs in said bores, a diskshaped head on said driven member adapted to be assembled in said body,a plurality of friction elements carried by Said body intermediate thesai-d members said friction elements comprising a set of vdisks mountedon each of the said members for rotation therewith, the said sets ofdisks being disposed alternately in overlapping arrangement, one of theVsaid sets of disks on one of the said members being formed of ferrousmaterial ing formed of non-ferrous metal having graphite mixed therewithmeans mounted in the bores in said shoulder portion for resilientlythrusting the said friction means in said bores into frictionalengagement, and means for selectively regulating the pressure exerted bythe said resilient thrust means against the friction means.

4. In mechanism of the character described, a pair of interfitting maleand female members adapted to constitute driving and driven members, aplurality of friction elements fixed to the said respective members,said friction elements comprising a set of disks mounted on each of thesaid members for rotation therewith, the said sets of disks beingdisposed alternately in overlapping face engaging relation to each othera shoulder portion on said female member, vertical bores in saidshoulder portion, one of the said sets of disks being formed of ferrousmaterial and the other set being formed of non-ferrous metal havinggraphite mixed therewith and selectively adjustable means in said boresfor exerting pressure axially against the said friction elements.

5. In mechanism of the character described, a driving member acylindrical body on said member, a shoulder portion on said body, adriven member co-axially related with the driving member, a set of disksmounted on each of the said members for rotation therewith, the saidsets of disks being disposed alternately in overlapping arrangement, oneof the said sets of disks being formed of ferrous material and the otherset being formed of non-ferrous metal having graphite mixed therewith,and means carried by the shoulder portion of' said female member forexerting pressure resiliently against the disks for continuallymaintaining the overlapping faces in frictional contact. y

6. In mechanism of the character described, a

female section having axially extending ribs therein, a plurality ofdisks mounted transversely in the said section having notches in theperiphery thereof slidably engaging the said ribs, a male sectiondetachably connected in co-axial relation with the female section andhaving a noncircular stud projecting into the female section, aplurality of disks having non-circular central openings slidably fittedon the stud and making non-rotary connection therewith, the said lastmentioned disks being disposed alternately with the first mentioneddisks said female section comprising a cylindrical body, a shoulderportion on said body, vertical bores in said shoulder portion, one ofthe said sets of disks being formed of ferrous material and the otherset being formed of non-ferrous metal having graphite mixed therewith,means carried by the bores in the shoulder portion of the female sectionexerting axial pressure against the said disks to maintain the same infrictional engagement, and means for selectively regulating the pressureexerted by the said pressure means.

7. In mechanism of the character described, a cylindrical section openat one end and having an axially extending shank at the opposite end ashoulder portion on said section, vertical bores in said section, a pairof axially extending ribs formed in the said section, a plurality ofdisks slidably fitted in transverse positions in the section and havingnotches engaging the said ribs, a complementary section having a diskhead removably tted Within the open end of the cylindrical sectionhaving an outwardly projecting axial shank, an inwardly projecting studformed on the said head co-axially with the shanks and non-circular incross section, a plurality of disks slidably tted on the said stud andhaving nonrotary engagement therewith, the said last mentioned disksbeing disposed alternately -between the first mentioned disks, one ofsaid sets of disks being formed of ferrous material and the other setbeing formed of non-ferrous metal having graphite mixed therewith, apair of coiled compression springs mounted in the bores in the shoulderportion on the cylindrical section and operative to exert pressure onthe disks to maintain the same in frictional engagement, and holdingscrews mounted in the bores in the shoulder portion on the saidcylindrical section retaining the said springs in pressure applyingposition and adjustable to regulate the pressure exerted by the springs.

FRANK ALDEN MlLLER.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,241,117 Hopkins Sept. 25, 19171,503,446 Hedglon July 29, 1924 2,256,062 Taylor Sept. 16, 19412,260,593 Wittlinger et al. Oct. 28, 1941 2,323,355 Ricciardi July 6,1943 2,333,980 Branson Nov, 9, 1943 FOREIGN PATENTS Number Country Date19,710 Australia 1934 533,842 Great Britain 1941

